Field of the Invention
The present invention relates to a cooling system for an eco-friendly vehicle, and more particularly, to a cooling system that cools a stack, electric power components, motors, and an air conditioner coolant in a fuel cell vehicle, or cools electric power components, motors, and an air conditioner coolant of a hybrid vehicle or an electric vehicle.
Description of Related Art
Fuel cells have the advantage of generating electricity without environmental pollution, because they produce little air pollutants and carbon dioxide, and also have higher electricity generation efficiency than thermal power generation of the related art, such that eco-friendly vehicles using a fuel cell as the power source have been increasingly developed.
Meanwhile, hybrid vehicles can appropriately use power from a motor and an engine to drive the vehicles in accordance with traveling conditions of the vehicles, and the technology of driving a vehicle with a motor is necessary for the fuel cell vehicles.
It is a problem in driving a vehicle with a motor to dissipate heat generated by the operation of the motor and heat generated by phase change of current in an inverter.
Therefore, it is technologically necessary to cool electric power components, such as the motor and the inverter, and effectively cool the stack of the fuel cell, in fuel cell vehicles.
FIG. 1 is a diagram illustrating a cooling system of a fuel cell vehicle in the related art, which includes a cooling circuit composed of separate water pump, reservoir tank, and radiator for cooling electric power components and a cooling circuit composed of separate water pump, reservoir tank, and radiator for cooing a stack, in which an air-cooling type AC condenser is disposed between the radiators to cool an air conditioner with a cooling fan.
Further, the cooling system shown in FIG. 2 is a water-cooling type that cools the AC condenser with water, in which a separate cooling circuit composed of a water pump circulating cooling water to the water-cooling type air conditioner, a reservoir tank, and a radiator for cooling an AC coolant is included and the radiator for cooling an AC coolant is disposed between the stack-radiator and the electric power components-radiator to cool them with a cooling fan.
In the cooling systems in the related art, the configuration shown in FIG. 1 has difficulty in ensuring sufficient cooling performance, because the air-cooling type AC condenser increases ventilation resistance for the electric power components-radiator and the stack-radiator. In particular, the electric power components and the stack are operated at low temperature as compared with the existing internal combustion engines and require a high-capacity radiator because the enthalpy is very larger than the internal combustion engines, but the increase of thickness of the radiator increases ventilation resistance and decreases the amount of heat dissipation, such that a technology of arranging a cooling module and optimizing the capacity, considering the operational temperature of the electric power components and the stack is required.
On the other hand, the configuration shown in FIG. 2 has a problem that it needs too many parts, such as a radiator, a water pump, and a reservoir, by forming cooling circuits for the stack, electric power components, and the AC condenser, decreases the cooling effect by repeatedly arranging heat exchangers, and has an adverse effect on weight, arrangement of parts, and manufacturing cost of a vehicle.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.